This invention relates generally to the field of household appliances and more particularly to providing latching mechanism for locking the door of an appliance in a closed position during a cycle of operations to prevent operator access to moving parts.
Various appliances which have previously included door latching devices have generally provided a variety of solenoid actuated devices wherein the door is latched during specific portions of a cycle of operations. These appliances generally have included a door with a catch or other member which is engageable with a switch to condition the circuitry of the appliance for operation.
Conlee, U.S. Pat. No. 2,910,317, discloses a solenoid which is actuated to pull a tongue associated with a bolt into engagement with a slot in the latch element of the cover to positively lock the cover in place. The cover is locked only during high speed spin.
Beller et al, U.S. Pat. No. 3,272,935, is another example of a lid latch which is actuated only during the spin portion of a cycle of operations. The latch member will pivot a switch actuating lever to close the switch when the lid is closed. The electromagnet is not actuated for pivoting the latch lever into engagement with the latch until the spin cycle has begun. If the switch is not closed, the machine will not spin.
Grabek, U.S. Pat. No. 3,627,960, shows a keeper which extends downwardly through an aperture in a flange to close a switch as the lid is closed. This action conditions the appliance circuitry so that the solenoid can be actuated during the cycle to engage the locking leg of the latch with the keeper.
Filipak, U.S. Pat. No. 3,638,457, includes a solenoid actuated lid latch which prevents opening of the lid during spin. Also, the spin cycle cannot be initiated if the lid is open. A catch on the lid closes a lid switch.
Harrold, U.S. Pat. No. 3,763,670, teaches an automatic clothes washing machine where closing the access lid allows a keeper to strike an anvil which moves downwardly to rotate a latch which moves a slide to actuate a first switch. Actuating the first switch energizes a solenoid, if an associated timer switch is closed, to move a locking arm into engagement with the slide to lock the access lid and close a second switch. The first and second switches as well as the solenoid are in the spin circuit of the drive motor and combine to assure that the washing machine cannot be operated in the spin portion of the cycle unless the access lid is closed. The second switch and solenoid, are operable only during the spin portion of the cycle.
There have thus been shown a number of solenoid actuated door latches for appliances which are energized only during specific portions of the cycle. These latch mechanisms generally include apparatus for actuating a line or door switch which will condition the appliance circuitry for operation. The present application provides a latching mechanism controlled by a microcontroller and including means for sensing that the access door is in a closed and lockable posture. Upon locking the access door, switch means provides a signal to the microcontroller that the access door is closed and locked.